Perpendicular magnetic recording write head with enhancement capacitor on slider body for write current overshoot at write current switching

Abstract

Write enhancement circuitry on the head carrier of a magnetic recording disk drive provides additional write current overshoot beyond that provided by the write driver circuitry. An enhancement capacitor is formed with a dielectric layer between two layers of electrically-conductive magnetically-permeable shield material that serve as the capacitor plates. The write enhancement circuitry may also include an enhancement resistor. The enhancement capacitor and resistor are connected between the two terminals on the head carrier that connect to the write head coil. The capacitor and resistor are fabricated on the head carrier at the same time and in the same process as the read head. The first and second capacitor plates are generally coplanar with and formed of the same electrically-conductive magnetically-permeable material that forms the first and second magnetic shields for the read head. The enhancement resistor is a stack of layers that is coplanar with and formed of the same materials as the stack of layers that form the sensor portion of the read head between the two magnetic shields.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]This invention relates generally to perpendicular magnetic recording systems, and more particularly to a system with fast switching of the magnetization direction of the perpendicular write head.[0003]2. Description of the Related Art[0004]Perpendicular magnetic recording, wherein the recorded bits are stored in a perpendicular or out-of-plane orientation in the recording layer, allows for ultra-high recording densities in magnetic recording hard disk drives. The write head must be able to write data not only at high bit-density but also at high data-rates. The write speed is particularly important in enterprise disk drives. However, the switching time for the write pole of the write head to switch from one magnetization direction to the other is a limiting factor as the data rate is increased. At high data-rates, the available magnetic flux from the write head, as seen by the recording layer on the disk, is limited by ...

AI Technical Summary

Benefits of technology

[0008]The first and second terminals on the head carrier are adapted for connection to a write driver that has a voltage VD and resistance RWD for supplying a write current to the write head, wherein the write head has an inductance LH and resistance RH. With the write enhancement circuitry on the head carrier, the write head has a write current response with an attenuation constant α=1 / [2(RWD+RE)CE]. Proper selection of the values of the enhancement resistance RE and capacitance CE during fabrication enable the desired degree of damping (time constant) to be chosen. The resistance RE can be increased such that the amount of write current overshoot can be decreased (tuned down) for a given capacitance CE. Eventually, with larger RE values (RE>>RWM), the amount of overshoot from the enhancement capacitance CE is negligible.

Problems solved by technology

However, the switching time for the write pole of the write head to switch from one magnetization direction to the other is a limiting factor as the data rate is increased.

Images